For obvious safety reasons, it is important for the tyre to be correctly inflated, for it not to be overloaded and for it not to be too worn. This is because pronounced wear of the tyre tread, an overload or underinflation risk causing a puncture, a blow-out, hydroplaning on a wet road, the loss of endurance, overheating, and other such problems.
To facilitate the monitoring of the condition of the tyre, it is commonly provided with condition indicators.
An example of a condition indicator for monitoring the wear consists of a rib provided at the bottom of a groove in the sculpture of the tyre and the height of which corresponds to the minimum depth of the grooves of the tyre required for correct and safe operation of the tyre. Thus, when the tyre tread of the tyre is worn and the top of the rib is flush with the outer surface of the tyre tread, this means that the minimum depth accepted for the grooves has been reached, or even exceeded. It is therefore urgent to replace the tyre for safety.
One drawback to this type of condition indicator is that it requires the vigilance of the driver of the motor vehicle and regular visual monitoring of the condition of its tyres. As it happens, many drivers omit to carry out such checks and change their tyres too late, when, during a technical inspection of the vehicle, the garage mechanic checks the state of wear of the tyres or their pressure.